I have only had first hand dealings with the 2ltr SAAB lump of this generation, but can well image the 2.3ltr will be a very nicely designed, engineered and executed piece of hardware. 2.3ltr is still a thin walled cast iron block right? Rigidity is the king here, and the 2ltr certainly had it spades. I have other engine preferences, but that is what makes it all interesting and adds character.
However, if we are really going to consider engines on a like-for-like, then we need to consider BMEP figures only, and that at peak power and peak torque. Then we'll have a meaningful comparative measure, need to wean ourselves from BHP numbers alone (DIN/SAE etc), otherwise we would be better off talking torque. Then to balance things out for different engine constructions we could factor weight, and normalise the numbers - could consider any engine, size, configuration or number of cylinders.
Look up SAE document 640664 Small High Speed, High Performance Gasoline Engine, old now but makes very good comparisons graphically of several generations of engines. I think you should be able to find this one the net, I’m a member so it’s easy for me. There’s another good one for F1, and surprisingly enough, when the revert back to n/a the rate of progression in terms of output is surprisingly level considering the incredible advancement of technology, materials, coatings, lubrication, air-spring valve control, electronics, fuels, you name it… So there really are no magic engines as such – in the more refined designs, excluding the boners… just better packages for particular applications… Except of course the latest Fiat engine soon to be released, with completely variable hydraulic valve control- lift and duration etc, finger followers, high rpm, lovely piece of kit.. ha-ha+
sorry couldn't help the last bit, this was all getting too serious!!!